In secret bay, towards the end of our dive, we spotted this mimic octopus that had dug itself into the sand. This was a few meters away from the blue-ringed octopus, with whom I had already spent much time. We knelt on the sand and waited for quite a while for the mimic to emerge.. until I suddenly realised that I was literally sucking on an empty tank (90 minutes into the dive). Came up with zero bar, 93 min dive, and, sadly, no other photo of the mimic.